The present invention relates to packaging including a sidewall or sidewalls constructed of flexible sheet(s) of material enclosed by end caps assembled from a foldable sheet material. More particularly, the end caps of the present invention are easily and quickly manufactured and assembled from inexpensive sheet material (e.g., paper, plastic, E-flute (cardboard) etc.).
One way of packaging an item for sale is to provide packaging that includes at least one wall member with a transparent window portion. A shopper can view the product being sold through the transparent window portion of the wall of the packaging. The wall can be constructed from multiple materials. For example, the wall of the packaging can be made from cardboard while the transparent window portion can be made from a transparent plastic.
A simple efficient product packaging structure can include a wall made entirely of the same material. Because at least a portion of the wall must be transparent, the wall could be made entirely from a transparent material or could be made from a transparent material that is partially colored leaving a transparent window. If an entire wall is formed from the transparent material, the material would generally need to have structural properties to adequately maintain the structural integrity of the packaging at least under normally anticipated modes of use of the packaging.
From a cost perspective, generally, the thinner the packaging is, the more cost effectively the packaging may be manufactured. However, generally, the thinness of a wall material is inversely proportional to the structural integrity it provides. Therefore a balance must be achieved that provides a minimal desired structural performance while minimizing material and manufacturing costs.
A cylindrical tube with no end caps (e.g., made from a thin flexible sheet of acetate) has different strengths in different modes of use. Generally, the tube is relatively weak when compressed inwardly in the radial direction and in the middle of its length. The tube is even weaker when compressed inwardly in the radial direction at the end of a tube with no end caps. In contrast the tube is relatively strong when loaded evenly in the longitudinal axial direction (the same compressive mode as loading a column in a building).
When end caps are added to a cylindrical tube, the wall's performance improves. The tube wall becomes stronger when compressed inwardly in the radial direction and in the middle of the tube's length. The tube also becomes even stronger when compressed inwardly in the radial direction and at the end of the tube near the end cap. Therefore, simply adding end caps to a cylindrical wall made of thin sheet material can dramatically increase the structural integrity of a product package in significant modes of use.
Creating a wall from a thin flexible transparent material can accomplished cheaply and simply. Therefore, what remains is to create a simple structurally and functionally sound end cap that can be easily and cheaply manufactured. Other end caps for flexible transparent containers have been made from a variety of materials of varying costs. However, there is a long felt need to develop an end cap having a structure permitting easy and cost effective manufacture and assembly.